A steam boat goes across a lake and comes back $(a)$ On a quite day when the water is still and $(b)$ On a rough day when there is uniform air current so as to help the journey onward and to impede the journey back. If the speed of the launch on both days was same, in which case it will complete the journey in lesser time
A steam boat goes across a lake and comes back $(a)$ On a quite day when the water is still and $(b)$ On a rough day when there is uniform air current so as to help the journey onward and to impede the journey back. If the speed of the launch on both days was same, in which case it will complete the journey in lesser time
- A
Case $(b)$
- B
Case $(a)$
- C
Same in both
- D
Nothing can be predicted
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- [JEE MAIN 2022]
$Assertion$ : The magnitude of velocity of two boats relative to river is same. Both boats start simultaneously from same point on one bank may reach opposite bank simultaneously moving along different paths.
$Reason$ : For boats to cross the river in same time. The component of their velocity relative to river in direction normal to flow should be same.
$Assertion$ : The magnitude of velocity of two boats relative to river is same. Both boats start simultaneously from same point on one bank may reach opposite bank simultaneously moving along different paths.
$Reason$ : For boats to cross the river in same time. The component of their velocity relative to river in direction normal to flow should be same.
- [AIIMS 2015]
A man crosses a $320\, m$ wide river perpendicular to the current in $4$ minutes. If in still water he can swim with a speed $5/3$ times that of the current, then the speed of the current, in $m/min$ is
A man crosses a $320\, m$ wide river perpendicular to the current in $4$ minutes. If in still water he can swim with a speed $5/3$ times that of the current, then the speed of the current, in $m/min$ is